The present invention relates to a seat system.
Conventionally, a tensioner mechanism that can improve the restraint function of a passenger by winding a seatbelt when a vehicle crash is detected or predicted is known. Japanese Patent Laid-Open Publication No. 2000-233713, for example, discloses a pretensioner as such a tensioner mechanism, which winds a shoulder belt of the seatbelt when the vehicle rear crash is detected or predicted.
Meanwhile, it is known that a seat comprises a movable portion that is provided so as to change its position to a specified position in order to protect the passenger when a vehicle crash is detected or predicted. In the above-described patent publication, for example, a headrest as such a movable portion is disclosed. That is, this headrest is configured to move upward, or forward and upward obliquely when the vehicle rear crash is detected or predicted, thereby stably holding a head of the passenger to be pushed rearward with the seatbelt-winding operation of the above-described tensioner mechanism.
Herein, it may be necessary to provide a drive source, such as a drive motor or a powder-explosion type of inflator, to drive the above-described movable portion. The above-described patent publication discloses a seat equipped with a particular drive source for the headrest. However, the structure of this seat with such the particular drive source would become improperly complex.